Recently, bulbs of head lamp lighting system of a vehicle have been replaced by strings of Light-Emitting Diodes (LEDs). LEDs for head lamp lighting system are generally high power LEDs in order to be used for high beam, low beam or other outside lighting functions of a vehicle. Generally, battery voltages of vehicles are not suitable as such for providing electrical power to said head lamp lighting system. Battery voltage of a vehicle is generally not stable as it may vary under operating conditions of the vehicle. Battery voltage level is also generally not suitable for high power LEDs.
It is known to use step-up converter for providing power supply to head lamp lighting device. However, said step-up converter generates heat and are generally not suitable for a wide diversity of LEDs functions as high beam, low beam, turn indicators, day running lights, fog lights, etc.